Notes 5.1 Passive Transport

1. Notes 5.1 Passive Transport Page 97

2. With your table: 1) Watch this video. 2) Answer these questions: a) What is this organism? b) What is the organism doing? c) You know a little about the structure of cell membranes. How is this possible?

3. Standards: CLE 3210.1.5 - Compare different models to explain the movement of materials into and out of the cell. SPI 3210.1.8 - Compare active and passive transport. RLE 2010.2.1 - Recognize the importance of homeostasis as a survival mechanism.

4. Objectives (today I will…) Analyze the importance of homeostasis to an organism’s survival Differentiate the different types of passive transport Compare active and passive transport Explore factors that affect passive transport

5. Homeostasis • Define homeostasis: • Macro example: • Micro example: a relatively stable state of equilibrium or a tendency toward such a state We maintain a stable body temperature. Cells use the cell membrane to regulate what comes in and out of the cell to keep steady levels of nutrients, water and other substances.

6. Cell Membrane Transport • Two main types of cell transport: • Passive: • Active: the movement of substances across a cell membrane without the use of energy. the movement of chemical substances, usually across a cell membrane that requires the use of energy.

7. Types of Passive Transport(uses no energy) • Diffusion • Osmosis • Facilitated Diffusion Movement of solutes from an area of high concentration to an area of lower concentration. Movement of water molecules from an area of high water concentration to an area of lower water concentration. Diffusion of molecules across a membrane through channels and pores from an area of high concentration to an area of lower concentration.

8. Concentration Concentration: Two parts needed to determine concentration: • Solvent: • Solute: the amount of a substance in a given volume The substance in the greatest volume, it is what the solute is dissolved in. The substance in the smaller volume, it is the substance(s) that are dissolved in the solvent.

9. Concentration Example Example: Salt water • Solvent? • Solute? Water Salt

10. Concentration Gradient What is a gradient? change in the value of a quantity (as temperature, pressure, or concentration) with change in a given variable and especially per unit distance in a specified direction

11. Passive Transport = High to Low Why will things move from high concentration to low concentration? All molecules are moving. As they bump into each other they move faster until there is even space between them.

12. Passive Transport = Equilibrium • Equilibrium: When the concentration of molecules is the same throughout the space the molecules occupy.

13. Activity Hanna– Can you smell the air freshener? How did that happen?

14. How does this affect cells? • Diffusion: • Osmosis: Solutes like oxygen, carbon dioxide, and other small molecules can get in or out of the cell with no energy needed. Water can move freely in and out of the cell depending on its environment. (Can be good or bad depending on the environment.)

15. Video: • Watch the video and answer these questions with your table. • Describe what you see happening to the cells. • Relate this to the fact that the cell has a permeable membrane.

16. Facilitated Diffusion (Passive) • Definition: • Video - "Facilitated Diffusion” Diffusion of molecules across a membrane through channels and pores from an area of high concentration to an area of lower concentration.

17. Passive Transport Review: Three types: • Diffusion: • Osmosis: • Facilitated diffusion: Common Characteristics: • Don't use any energy • Move from high to low concentration small solutes (O2 or CO2) moving across the membrane movement of water across the membrane larger solutes (glucose) moving across the membrane through channels or pores

18. Exit Ticket (a 1/2 piece of paper) • What is the difference between regular and facilitated diffusion?